The present invention generally relates to an inventory (stock)control technique. More specifically, the present invention is directed to an inventory control system, an inventory control method, and an inventory control program, capable of setting safety stock (safety inventory), and also, is directed to a method for collecting a use fee of this inventory control program, and a storage medium for storing thereinto the inventory control program.
Inventory amounts of items such as products and parts are required to be controlled in correspondence with demands for these items, while these items designate a general term with respect to products, parts, components, half-made products, unfinished products (or in-process items), and materials, or designate any one of these products/materials. In general, however, since demands are continuously varied, when inventory amounts are determined, excessive inventory amounts must be secured in order to be capable of accepting these demand variations. Such an inventory capable of establishing safety by securing an excessive inventory amount will be referred to as “safety stock” hereinafter. Generally speaking, a formula of calculating a so-called “safety stock” may be expressed as follows:
safety stock=α×√T×σ, where symbols are defined by: α: safety factor, T: planned range, σ: fluctuation of demands (standard deviation).
In the above-described calculation formula, the planned range is obtained by totalizing a planning cycle, a procurement lead time, and a plan lead time. In this case, a term “lead time” implies such a time period that after an order is issued, a work is carried out until this order is accomplished. FIG. 39 and FIG. 40 represent a relationship among the planned range, the planning cycle, the procurement lead time, and the plan lead time. In the example shown in FIG. 39, the plan lead time corresponds to 2 days; the procurement lead time corresponds to 4 days; the planning cycle corresponds to 7 days; and the planned range corresponds to 13 days obtained by totalizing these days. Also, in the example shown in FIG. 40, the plan lead time corresponds to 2 days; the procurement lead time corresponds to 4 days; the planning cycle corresponds to 1 day; and the planned range corresponds to 7 days obtained by totalizing these days.
To set safety stock, arbitrary values are substituted for “α”, “T”, and “σ” of the above-explained safety stock calculation formula. Also, there is another method capable of setting arbitrary values as safety stock without employing the above-described safety stock calculating formula.
Next, a description will now be made of a conventional technique as to fee collecting methods of software.
As the conventional fee collecting methods for software, the below-mentioned fee collecting methods have been proposed:
(1) Fee Collecting Method in Product Purchasing Form:
In this fee collecting method, software which has been stored in a recording medium such as a floppy (R) disk and a compact disk is purchased so as to be used.
(2) Service-fixed-sum Fee Collecting Method:
In this fee collecting method, software itself is not purchased. A fixed sum is paid to a software providing company every predetermined time period (for example, every month) as a software lease fee, or a software use fee.
(3) Provided-service-sum Fee Collecting Method:
In this fee collecting method, software itself is not purchased. A fee is paid to a software providing company in response to time and a frequency at which the software is utilized.
In the examples indicated in FIG. 30 and FIG. 40, the plan lead time corresponds to 2 days; the procurement lead time corresponds to 4 days; and the planning cycles are 7 days and 1 day, respectively. Very recently, there is such a trend that since management environments are changed, manufacturing speeds of products are improved, and high-performance information systems have been developed, the above-described planning cycles, procurement lead time, and plan lead time are shortened. Furthermore, such chances for updating these cycles/lead times are increased. In general, when a planning cycle is shortened in unit of a week, or a day, an inventory amount may be reduced. On the other hand, if safety stock is mistakenly set, then product depletion may occur and/or excessive inventory may be increased. As a consequence, the following inventory control operation is necessarily required. That is, in this inventory control operation, while safety stock is changed in response to updating of such setting values as a planning cycle, a procurement lead time, and a plan lead time, the safety stock is continuously maintained as a proper value.
However, the above-described safety stock calculating formula explained in the conventional technique has been established based upon several assumptions, for example, it is so assumed that a remainder distribution of demand data is constant. As a result, there is no guarantee that the above-described safety stock continuously constitutes the proper value, while this safety stock has been acquired by substituting the planning cycle and the various lead times for this safety stock calculating formula. As a consequence, in order to calculate such a proper safety stock to which updating of the planning cycle and the various lead times may be correctly reflected, several pieces of featured calculating process operations must be carried out.
Next, problems as to the conventional software fee collecting methods will now be explained.
Currently, there is a trend that such client enterprises are increased which use various sorts of software, while utilizing outsourcing services provided by application service providers (will be referred to as “ASP” hereinafter) in order to reduce expenses required to purchase and maintain software. In the case that various sorts of software are used by utilizing outsourcing services, fee collecting methods for uses of desirable software are defined by selecting the above-explained (2) service-fixed-sum fee collecting method, or (3) provided-service-sum fee collecting method, or employing both these fee collecting methods (2) and (3) as explained in the conventional technique. In this selection case, generally speaking, there is such a trend that client enterprises may select either the service-fixed-sum fee collecting method or the provided-service-sum fee collecting method combined with this service-fixed-sum fee collecting method due to such a reason that these client enterprises may easily make up budgets for receiving software services.
However, these conventional fee collecting methods own the below-mentioned problems.
First of all, although the service-fixed-sum fee collecting method own such a merit that a service fee is fixed and a budget may be readily made up, this service-fixed-sum fee collecting method never corresponds to such a fee collecting system capable of detrmining a fee by checking as to whether or not software is essentially used. As a consequence, this service-fixed-sum fee collecting method may give advantages to such clients who use software for long time and at higher frequencies. However, this service-fixed-sum fee collecting method cannot give satisfaction to other clients who use software at lower frequencies.
Also, in such a case that the service-fixed-sum fee collecting method is combined with the provided-service-sum fee collecting method, clients necessarily pay use fees of software later after these clients have utilized the software. Accordingly, software providing forms always own some risks of collecting use fees from these clients.
As previously explained, the above-explained conventional fee collecting methods cannot give satisfaction with respect to both the clients who use the software at lower frequencies and also these software providing firms.